Electronics Forum | Mon Sep 20 16:06:53 EDT 2004 | blnorman
We require that the ovens used for bake out are vented, thus removing the vapor from the oven.
Electronics Forum | Wed Sep 15 22:44:58 EDT 2004 | pdeuel
RH changes with temprature. That's why your winshield de-fogs when your defroster is on.
Electronics Forum | Mon Sep 20 16:15:11 EDT 2004 | davef
The activation energy for diffusion for molded with novolac, biphenyl or multifunctional epoxy mold compounds and air are not equal.
Electronics Forum | Tue Sep 21 00:45:39 EDT 2004 | aaronrobinson
thanks Dave, do you know where I can read a little more on this?
Electronics Forum | Tue Sep 21 06:46:58 EDT 2004 | davef
Background on activation energy for diffusion can be found: * Materials textbooks * College lectures posted on the web. Use 'google' or someother search tool. As a guideline, the higher the activation energy, the harder is is for diffusion to occur
Electronics Forum | Sun Sep 19 19:51:31 EDT 2004 | aaronrobinson
thanks for your reply ....yes the air is then able to hold more water vapour.... but so is the component hence there is no water vapour pressure difference and the component and the air in the oven would still be in equilibrium???? hence no effective
Electronics Forum | Wed Sep 15 17:53:53 EDT 2004 | aaronrobinson
My question is how does heat alone (125DegC for 48hours) diffuse the water vapour in a component, I figure the amount of water vapour in grams per cubic cm will be the same regardless of temp...yes with temp the RH changes but once the component rea
Electronics Forum | Wed Jul 11 22:44:50 EDT 2012 | joeion
Why cannot reply????
Electronics Forum | Wed Jul 11 22:48:54 EDT 2012 | joeion
It is correct to remove moisture in PCB by baking. But I think the time and temperature is too little. According to our experience, it should be more than 60min at 120 centigrade degrees.
Electronics Forum | Thu Jul 12 02:15:53 EDT 2012 | thmeier
Check also the specs / recommendations of your PCB manufacturer. We bake boards 4h/120°C before reflow and after automated cleaning (it´s not FR4!) and also if we have to rework with the autometd rework- stations (massive IR underheating ,..). Regar
